The present invention relates to flanges, in particular for application in a watertight coupling of high and low pressure fluid pipes, whose outer surface is totally smooth, without any ribs or edges.
In particular the present invention relates to a flange with improved fitting and tightening, which considerably increases the resistance of the flange to different stresses caused due to passage of a pressurized fluid inside a conduit that may cause axial displacement in the pipes specifically at their coupling point with one another, with a subsequent decoupling and risk of leaks, and which reduces possibilities of damage to the surface of the pipes.
Flanges for a watertight coupling of smooth end pipes are known. Some of them are disclosed in Spanish Utility Models 235,619; U8600595, U8600609, U8600639, in Spanish patents P8803941, P9401300 and P9601830, and in British patents 1,462,886 and 1,582,858.
They disclose flange-based devices provided with suitable elements that guarantee the necessary water-tightness as well as a correct and permanent securing of the ends of the pipes coupled. However, they do not have elements that guarantee the aforementioned when pipes having totally smooth outer surface must be coupled. This is an important factor which must be taken into consideration when pipes are composed of thermoplastic materials, such as polyvinylchloride (PVC) or polyethylene (PE) and the surface of the pipes if also relatively soft and may be damaged depending on the type of coupling flange used.